1 files changed, 53 insertions, 0 deletions
diff --git a/tests/ui/generator/auto-trait-regions.rs b/tests/ui/generator/auto-trait-regions.rs
new file mode 100644
index 000000000..ea4b0d554
--- /dev/null
+++ b/tests/ui/generator/auto-trait-regions.rs
@@ -0,0 +1,53 @@
+#![feature(generators)]
+#![feature(auto_traits)]
+#![feature(negative_impls)]
+
+auto trait Foo {}
+
+struct No;
+
+impl !Foo for No {}
+
+struct A<'a, 'b>(&'a mut bool, &'b mut bool, No);
+
+impl<'a, 'b: 'a> Foo for A<'a, 'b> {}
+
+struct OnlyFooIfStaticRef(No);
+impl Foo for &'static OnlyFooIfStaticRef {}
+
+struct OnlyFooIfRef(No);
+impl<'a> Foo for &'a OnlyFooIfRef {}
+
+fn assert_foo<T: Foo>(f: T) {}
+
+fn main() {
+    // Make sure 'static is erased for generator interiors so we can't match it in trait selection
+    let x: &'static _ = &OnlyFooIfStaticRef(No);
+    let gen = || {
+        let x = x;
+        yield;
+        assert_foo(x);
+    };
+    assert_foo(gen);
+    //~^ ERROR implementation of `Foo` is not general enough
+
+    // Allow impls which matches any lifetime
+    let x = &OnlyFooIfRef(No);
+    let gen = || {
+        let x = x;
+        yield;
+        assert_foo(x);
+    };
+    assert_foo(gen); // ok
+
+    // Disallow impls which relates lifetimes in the generator interior
+    let gen = || {
+        let a = A(&mut true, &mut true, No);
+        //~^ temporary value dropped while borrowed
+        //~| temporary value dropped while borrowed
+        yield;
+        assert_foo(a);
+    };
+    assert_foo(gen);
+    //~^ ERROR not general enough
+}